Sewing machine



G T. HART, JR

Nov. 15, 1932.

SEWI NG MACHINE Filed Dec.

12, 1930 5 Sheets-Sheet 1 Nov. 15, 1932.

q. T. HART, JR 1,887,638.-

SEWING MACHINE s Sheets-Sheet 2 Filed Dec. 12, 1930 Wii'neJJ PatentedNov. 15, 1932 UNITED STATES PATENT-or ce GEORGE '1. HART, .73., or westLYNN, MAsseoHUsET'rsnssIeNoR T0 UNITED snoE MACHINERY CORPORATION, orPATERSON, NEW. JERSEY, A GORP RATION or NEW JERSEY SEWING MACHINEApplication filed December iai'eao. Serial No. 501,847. i

The presentinvention relates to machines for sewing soles to the uppersof boots and shoes, and particularly to that class known as McKay sewingmachines in which a hook needle penetrates the sole andenters theinterior ofthe shoe and'a horn is introduced into the shoe forsupporting the same and for conducting the thread to the sewing point.

In machines of this typeit is customary to thread the needle by means ofa needle threading whirl or looper 'rotatably mounted in the tip of thehorn and having motion imparted thereto from the sewing cam shaft in thehead of the machine byigear actuated mechanism, gear teeth being cut inthe periphery of the whirl .to provide a connection with said mechanism..While the whirl used in such machines has been reduced to the smallestpossible dimensions, the tip of the horn is still objectionably largefor some types of work and this situation'is unavoidable in machinesemploying a rotary whirl for threading the needle. 'In order to permitthe use of horns' with smaller tips than have heretofore been possible,thepresent invention has eliminated the needle threading whirl andprovided inits place a novel needle threading mechanism having novmoving parts and actuating mechanism therefor positioned in the horn. iThe novel needle threading mechanism comprises a horn having an openingfor the passage of the thread and for the reception of the needle point,and means for rotating the needle at the limit of its downward stroke inorder to cause the needle to engage the thread and carry it about theneedle'in order to lay a loop of thread in the needle barb. The needleis provided with a thread engaging surface in the form of one of theusual vertical grooves extending from the open eye towards the point ofthe needle, and the opening in the horn is of a size to closely fit theneedle so that the thread is confined within the thread engaginggrooveduring the rotation of the needle.

Another feature of the invention consists of a loop spreader forinsuring-the entrance of the needle into the thread loop during itsdownward stroke. In the present embodi ment of the invention the loopspreader con- 'sists "of a cam actuated finger adapted to engage theforward leg of the thread-loop and hold it distended as the needlecommences its downward stroke.

the novel constructions,combinations and arrangements of partshereinafter described and claimed, theadvantages of which will beunderstood by those skilled in the art from the following description.

Referring to the accompanying drawings illustrating the invention in itspreferred i form,'Fig.'1 is a front elevation of a chainstitchsewingmachinehaving my invention embodiedtherein, so much only of the machinebeing shown as is'necessary to an understanding of my invention; Fig.2is a side elevation showing the parts in the same position as in Fig. 1;Fig.3 is a sectional plan view taken on the line 3+3 of Fig. 1; Figs.4,5 and 6 are. Vertical sections of the horn illustrating the needle andthread in three positions during the needles rotation; Fig. 7 is asectional plan view taken on the'line 77 of Fig. 4; Fig. 8' is asectional plan View taken on the line 88 of Fig.6; and Fig. 9 is asectional ,elevationtaken on the line 99 of Fig. 1, several parts beingomitted. v

The drawings illustrate a shoe sewing ma chine such as that described inthe patent to E. P. Richardson No. 710,612, dated October 7, 1902, towhich patent reference may be had for all features of the machine notherein illustrated; 'Machines of this type employ av straight barbedneedle operated by crank connections with a horizontal-driving shaftextending longitudinally of the machine. The work is supported between afixed horn and a spring and cam actuated presser footautomaticallyadjustable for variations in thickness" of work. The lower limit of themovement of theneeclle is constant but the upper limit of movement isvaried in proportion to variations/in thickness of the work in order tocause the needle todraw through the work the exact amount of threadrequired for the formation of the stitch; Such variation in needlemovement is effected" through 1 connections between the needle and thepress-- 100 7 Other features of the invention consist'of er foot. Inorder to provide suficient time for threading the needle, a period oflost motion is provided at the lowerlimit of the movement of the needle.

Heretofore such machines have employed a needle threading whirl orlooper rotatably mounted in the tip of the horn. As has been stated, animportant feature of the present invention comprises a needlethreadingmechanism which requires no moving parts and actuating mechanism withinthe horn. As herein illustrated, this needle threading mechanismconsists of the rotatable needle 10 mounted in a chuck 12 and securedtherein bymeans of the set screw 14 and of a block 15 mounted in anopening in the horn 17 and held against upward movement by means of the.cap 19 secured to the upper surface of the horn which block has acentralperfora tion 21 for the reception of the point of the needle and for thepassage of the thread from the supply to the work. The use of the block15 does away with the needle threading whirl and the whirl actuatingmechanism thus simplifying the machine and permitting the use of a hornhaving a smaller tip than has heretofore been possible. The chuck 12 issupported within the tubular member 16 which is brazed to the reducedlower por tion 20 of the needle bar 18. The needle is rotated by therack-actuated pinion 24lfiXed to the shank 26 of the chuck and held inits position on the shank 26 between the shoulder 28 formed in saidshank and the nut 22.

The upperportion 36 ofthe'shank 26 is re-. duccd .to permit the nut 22to pass freely over it. The pinion 2a is held against rotation on theshank 26 by means of a pin 30 driven through said shank. The lower end4U of the pinion 24 bears freely upon the upper surface of a cap 32threaded to the lower end of the tubular member 16, and cooperates withthe shoulder 33 formed in the chuck to v maintain thechuck in itsvertical relation to the tubular member. The shank 26 is journalled inbearings inthe cap 32 and in the reduced lower portion 20 of the needlebar 18. Oil is delivered to the bearing surfaces of the chuck shank 26and pinion 2 l'cthrough an oil hole 88 in the needlebar 18.

- The pinion 24 is actuated by the rack 40, said rack and pinionhaving-an idler 42 inserted between them in order to space them apartfrom each other, said idler being rotate ably secured to the machineframe by the screw 43. The tubular member 16 is open at the rear thereofto permit the idler a2 to engage the pinion 24 (see Fig. 3). The rack 40 is supported within a guideway l4 formed in'a bracket a6 supported bythe screws l8 and'50 threaded to the under side of the head of themachine; An oscillating motio-nis iinparted to the rack by means of thecam 52 fixed to the cam shaft 54, said cam actuating the cam lever 56pivoted on the shaft 58,

which shaft is fixed tothe extension 59 of the machine frame by means ofa set screw 60.

rack l0 are sotimedthat the needle is rotated 270 degrees in a clockwisedirection, looking down at the needle, at the beginning of its downwardstroke, and 270 degrees in counterclockwise direction while the barb ofthe needle is positioned within the horn. The

latter rotation of the needle takes place during the interval oflostmotion when'the needle is vertically at rest, and leaves the needle withits open eye facing opposite to the direction of feed whereby thefeeding of the work willnottend to. draw the loop from the eye of theneedle. Referring again to the cam 52, the clockwisc rotation of theneedle will take place when the roll 62 is passing over the surface '50of said cam, and the counter-clock wise rotation of the needle will takeplace when the roll 62 is passing over the surface 7 2 of saidcam. Thespace 74 on the edge of the cam 52 between the surface 70 and 72represents'the interval of time when the needle is passing through thework, during which interval the needle must not rotate, as rotation ofthe needle during this interval would tend to cause the work to rotatewith the needle. During the greater part of the interval of lost motionandduring the upward stroke of theneedle which follows immediately aftersaid interval, the needle does not rotate. During this period of time,the roll 62 is passing over the surface 76 of the cam 52. p V

The roll 62 is held in engaging position with the cam 52 by means of aspring 78 coiled about the shaft 58, one end of said spring being heldbetweenthe collar 80 and the shaft 58, the other end engaging theextension Set of the horizontal portion 86 of the cam lever The needle10 is constructedso as to engage the thread during the counter-clockwiserotation at the end of its downward stroke. To. this end the needle isprovided with a thread engaging surface 88 in the form of one of theusual vertical grooves extending from the open eye toward the point ofthe needle (see Figs. 7 and 8). When the needle enters the horn at theend of its downward stroke, the needle barb 90 is in the positionindicated by F a andithe thread will be positioned within the groove 88in the surfacecf the needle.. During the counter-clockwise rotation ofthe needle the groove 88 will engage the thread and carry the threadwith it' during its liO rotation. At the end'of the counter-clockwiserotation of the needle, the needle and thread will be in the positionindicated by Figure 6, the thread being positioned within the bar-b ofthe needle. It is obvious that upon the upstroke of the needle thethread will becarried through the work by the needle.

- It is important that the opening 92 in the needle. In order toovercome this tendency and insure the entrance of the needle into theloop, the thread loop is spread open at the beginning of the downwardstroke of the needle by means of a loop spreader at the end of a rod 96,which rod is pivoted at 97 to the bracket 98 fixed to the machine frame.An oscillating motion is imparted to the loop spreader 94 by means of acam 100 fixed to the cam shaft 54, said cam actuating the cam lever 102,which lever in turn actuates the link 104 attached to the upper end ofthe rod 96. The cam lever 102 has a roll 106 rota-tably mounted therein,which roll is held in engagement with the cam 100 by means of a sprlng108 coiled about the shaft 110 which shaft is journalled to a bearing inthe lateral extension 111 of the forward end of the machine frame and toa bearing (not illustrated) in the rear of the machine frame.

The lever 102 is secured to the shaft 110 by means of the pin 112. Oneend of the coiled spring 108 is secured to the collar 114 fixed to theshaft 110. The other end of the coiled spring 108 bears upon a screw 116fixed to the extension 111 of the machine frame. A

lever 118 is fixed to the forward end of the shaft 110 by means of thepin 119 and has pivoted thereto at 120 the link 104, the other end ofwhich link is rotatably mounted in a yoke 122 fixed to the upper end ofthe rod 96. The thread engaging movement of the loop spreader takesplace when the cam roll 106 is passing over the cam surface 124,

" which takes place immediately after the needle has commenced itsdownward stroke, the loop spreader engaging the forward leg of thethread loop at approximately the point of time when the needle beginsits clockwise rotation. The above described timing of the loop spreaderis essential to its function since the thread would not be in positionto beengaged by the loop spreader after the needle had completed asubstantial part of its rotation. The loop spreader 94 returns to itsoriginal position at that interval during the upward stroke'of theneedle when the needle engaging surface 125 of the cast-off 126 ishorizontally in line with the loop spreader 94. It is essential that thec'ast-ofi'be atthis 30 point in its upward movement during the movementof the loop spreader since the loop spreader-brushes against thecast-off in its movement and would be caught between the cast-off andthe needle if the cast-off had not I reached the aforesaid point in itsupward movement when the loop spreader passed in front of the needle onits return movement. During said return movement of the loop spreader,the cam'roll 1 06 passes over the cam surface 128, which surface is madeshorter and steeper than the camsurface 124 in V orderthat thereturn'movement of theloop spreader maybe rapid. Return movement of theloop spreader must. berapid in order 35 to insure its passing across theneedle before the needle barb has reached a point of elevation abovethelevel of the loop spreader, but not before the cast-off reaches a polntin its upward movement where the needle ena gaging surface 125. of saidcast-oft will be 7 horizontally in line with the loop spreader. It isessential that the loop. spreader make its return movement not laterthan this exact instant of time in order that it may avoid contact withthe thread. i

What is claimed as the invention is 1 1. In a sewing machine, thecombination with the other sewing devices of a straight hook needleprovided with a thread engaging surface, a shoe receiving horn, anopening in the horn in line with the needle axis for the passage of thethread and for the reception of the point of the needle, means forrotating the needle on its axis at the limit of its downward stroke, andmeans for holding the thread in engagement with said threaden-' gagingsurface. I r

2. In a sewing machine, the combination with the other sewing devices'ofa straight hook needle provided with a thread engaging surface, a shoereceiving horn, an opening in the horn in line with the needleaxis forthe passage of the thread andfor the reception of the point of theneedle, means for, rotating the needle on its axis at thelimit of itsdownward stroke, and means for hold ing the thread in engagement withsaid thread engagings'urface comprising a thread engagingsurface formedin the horn.

3.111 a sewing machine, the combination with the other sewing devices ofa straight hook needle provided with a thread engaging surface, a shoereceiving horn,an opening int-he horn in line with the needle axis forthe passage of the thread and forthe reception of the point of theneedle, cam

and means for holding the thread in engagement with said thread engaging surface.

' 4. In a sewing machine, the combination with the other sewing devicesof a straight hook needle provided with a vertical thread engagingsurface and positioned during its upward stroke with its hook pointingin a direction opposite the direction of feed, ashoe'receiving horn, anopening in the horn in line with the needle axis for the passage of tnethread and for the reception of the point of the needle, means forrotating the needle on its axis at the limit of its downward stroke, andmeans for holding the thread in engagement with said vertical threadengaging surface.

1 5. In a sewing machine, the combination with the other sewing devicesof'a straight hook needle provided with a thread engaging surface, ashoe receiving horn, an opening in the horn for the passage of thethread and for the reception of the point of the needle, means forrotating the needle at the limit of its downward stroke, and means forholding the thread in engagement with said thread engaging surface, andmeans for spreading the thread loop in order to cause the needle toenter the loop during its downward stroke.

6. In a sewing machine, the combination with the other sewing devices ofa straight hook needle provieed with a thread engaging surface, a shoereceiving horn, an opening in the horn for the passage of the thread andfor the reception of the point of the needle, means for rotating theneedle at the limit of its downward stroke, and means for holding thethread in engagement with said thread engaging surface, and a camactuated finger for spreading the thread loop in order to cause theneedle to enter the loop during its downward stroke.

7. In a sewing machine, the combination with the other sewing devices ofa straight hook needle, circular in cross section provided with a threadengaging surface, a shoe receiving horn, a circular opening in the hornin line with the needle axis for the passage of the thread and for thereception of the needle in closely fitting relation, and means forrotating the needle on its axis at the limit of its downward stroke.

8. In a sewing machine, the combination with the other sewing devices ofa straight hook needle provided with a. thread engaging surface, a shoereceiving horn, an opening in the horn in line with the needle axis forthe passage of the thread and for the reception of the point of theneedle, means for rotating the needle on its axis at the limit of itsdownward stroke, and means for holding the thread in engagement withsaid thread engaging surface comprising a thread engaging surface formedin the horn, and means for imparting a reverse rotation to the needle atthe'beginning of its downward stroke.

9. In a sewing machine, the combination with the other sewing devices ofa straight hook needle provided with a thread engaging surface, a shoereceiving horn,an'opening in the hornin line with the needle axis forthe passage of the thread and for the reception of the point of theneedle, means for rotating the needle on its axis at the-limit of itsdownward stroke to bring it to a position in which the hook points in adirection opposite to the direction of feed, means for holding thethread in engagement with said thread engaging surface comprising athread engaging surface formed in the horn, and means for imparting areverse rotation to the needle at the beginning of its downward strokethrough substantiallythree fourths of a revolution.

In testimony whereof I have signed my name to this specification.

GEORGE T. HART,

